Unix Timestamp Converter epoch
Convert between Unix timestamps in seconds or milliseconds and human-readable dates, with time zone comparison.
What this tool does
A Unix timestamp counts the time elapsed since 1 January 1970 00:00:00 UTC as an integer number of seconds. Because it is an absolute reference unaffected by time zones or daylight saving, it is the standard way to store an instant in databases, logs, and APIs.
The usual source of confusion is the unit. Unix systems, PHP, and most databases use seconds, while JavaScript Date.now() and Java use milliseconds. Second values currently have ten digits and millisecond values have thirteen, which is the quickest way to tell them apart. Misreading the unit produces dates in 1970 or tens of thousands of years in the future.
This tool recognises both units, converts in either direction, and shows UTC alongside local time so differences between server and client can be checked directly.
When to use it
Use it to turn a timestamp in a log into a wall clock time, to review created-at or expires-at values from an API, to interpret JWT exp and iat claims, to obtain the timestamp for a specific date to use in a query, or to compare server time against local time.
Input and output examples
1715155200
2024-05-08 08:00:00 UTC / 2024-05-08 17:00:00 KST
Ten digits means seconds. KST is nine hours ahead of UTC.
1767225600
2026-01-01 00:00:00 UTC
The shape of value you meet in a JWT exp claim.
1715155200000
2024-05-08 08:00:00 UTC (millisecond input)
Thirteen digits are treated as milliseconds, as produced by Date.now().
Notes and limitations
Always confirm which time zone a converted value refers to. The same timestamp is nine hours apart between UTC and KST, and missing that difference during an incident means searching the wrong window of logs. Systems that store timestamps in 32-bit signed integers also cannot represent times beyond January 2038, known as the Year 2038 problem.
Frequently asked questions
The result shows 1970.
A millisecond value was probably read as seconds, or the value is near zero. Check the digit count: ten for seconds, thirteen for milliseconds.
There is a nine-hour gap from my server time.
The server is most likely running in UTC. Korea Standard Time is UTC+9, so the difference is expected.
What is the Year 2038 problem?
Timestamps stored as 32-bit signed integers cannot represent times after 19 January 2038. Using 64-bit integers resolves it.